SEC Filings

College
of Medicine, University of Texas Southwestern Medical Center, University of Utah and Washington University School of Medicine.

Top-Line Results of Phase 1 Clinical Trial of AVXS-101 for the Treatment of SMA Type 1

In our fully enrolled Phase 1 clinical trial, we treated 15 SMA Type 1 patients, divided into two dosing cohorts, and observed a
favorable safety profile and that AVXS-101 was generally well-tolerated. As of August 7, 2017, all patients in the trial survived event free at 20 months of age, in contrast to the 8%
event free rate at this time point demonstrated in an independent, peer-reviewed natural history study for patients with SMA Type 1, which is known as PNCR. Additionally, we observed improved
motor function, including in some patients, the attainment of
motor milestones such as the ability to sit unassisted, crawl, stand and walk  motor milestone achievements that are essentially never seen among untreated patients suffering from
SMA Type 1. The open-label, dose-escalating trial was designed to evaluate the safety and tolerability of AVXS-101 in patients with SMA Type 1. The key measures of efficacy were the time
from birth to an "event", which was defined as either death or at least 16 hours per day of required ventilation support for breathing for 14 consecutive days in the absence of acute reversible
illness or perioperatively, and video confirmed achievement of ability to sit unassisted. Additionally, several exploratory objective measures were assessed, including a standard motor milestone
development survey and CHOP INTEND. At the study cutoff on August 7, 2017, patients in the proposed therapeutic dose cohort were observed to have a mean increase in CHOP INTEND scores of
24.6 points from a mean baseline of 28.2 points.

Recent Developments

End-of-Phase 1 Meeting and Alignment with the FDA on Next Steps Towards BLA Submission

On January 4, 2018, we provided an update following the receipt of minutes from our end-of-Phase 1 meeting with the FDA regarding
AVXS-101 for the treatment of SMA Type 1, at which the FDA reviewed our non-clinical, clinical and CMC data generated as of the date of the briefing package submission for the meeting with the
FDA. The FDA provided detailed information requests in each of the areas discussed, and we intend to submit the requested information to our investigational new drug application on an ongoing basis.
We will also provide the FDA with any additional clinical data available, including from our ongoing pivotal STR1VE trial and our Phase 1 SMA Type 2 IT STRONG trial. We intend to request
a pre-BLA meeting for AVXS-101 for SMA Type 1 with the FDA in the second quarter of 2018.

Amendment to License Agreement with REGENXBIO for SMA

On January 8, 2018, we entered into a First Amendment, or the Amendment, to our License Agreement dated March 21, 2014, or the
License Agreement, with REGENXBIO Inc., or REGENXBIO. Under the Amendment, REGENXBIO granted us an exclusive, worldwide commercial license, with rights to sublicense, to any recombinant
adeno-associated virus, or AAV, vector in
REGENXBIO's intellectual property portfolio during the term of the License Agreement for the treatment of SMA in humans by in vivo gene therapy. Under
the original License Agreement, REGENXBIO had granted us a license relating only to the AAV9 vector.

Additionally,
the Amendment modifies the terms and conditions of the License Agreement relating to assignment. Under the amended assignment provision, we are permitted to transfer the
License Agreement without REGENXBIO's consent in connection with a change of control of AveXis, subject to the transferee or successor agreeing in writing to be bound by the terms of the License
Agreement and the payment to REGENXBIO of certain fees due upon such change of control, as described below. Under the original License Agreement, any assignment by us,